December weather forecast and climate
Williamstown, MA

Weather in December

The first month of the winter, December, is also a wintry month in Williamstown, Massachusetts, with average temperature varying between 32.7°F (0.4°C) and 22.1°F (-5.5°C).

Temperature

In December, the average high-temperature decreases, from a frosty 43.7°F (6.5°C) in November, to a cold 32.7°F (0.4°C). In Williamstown, in December, the average low-temperature is 22.1°F (-5.5°C).

Humidity

In December, the average relative humidity in Williamstown is 85%.

Rainfall

In Williamstown, during December, the rain falls for 11.1 days and regularly aggregates up to 3.19" (81mm) of precipitation. In Williamstown, during the entire year, the rain falls for 167.1 days and collects up to 35.98" (914mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Williamstown, during 11.2 snowfall days, 6.93" (176mm) of snow is typically accumulated. Throughout the year, there are 66.1 snowfall days, and 39.09" (993mm) of snow is accumulated.

Daylight

With an average of 9.1h of daylight, December has the shortest days of the year.

Sunshine

In December, the average sunshine is 3.8h.

UV index

February and December, with an average maximum UV index of 1, are months with the lowest UV index in Williamstown. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to the Sun's UV rays for average individuals.
Note: In December, the average maximum UV index of 1 translate into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
[Resources]

FAQ

What is the average humidity in December in Williamstown?

In Williamstown, the average relative humidity in December is 85%.

How many days does it rain in December in Williamstown?

In Williamstown, Massachusetts, in December, it is raining for 11.1 days, with typically 3.19" (81mm) of accumulated precipitation.

How much does it snow in Williamstown in December?

In Williamstown, Massachusetts, in December, during 11.2 snowfall days, 6.93" (176mm) of snow is typically accumulated.

What is the month with the shortest days in Williamstown?

December has the shortest days of the year, with an average of 9.1h of daylight.

How many hours of daylight does Williamstown have in December?

In December, the average length of the day in Williamstown, Massachusetts, is 9.1h.

How long on average sun shines in December in Williamstown?

In Williamstown, Massachusetts, the average sunshine in December is 3.8h.

What is the month with the lowest UV index in Williamstown?

Months with the lowest UV index in Williamstown, Massachusetts, are February and December, with an average maximum UV index of 1.

How high is the UV index in December in Williamstown?

In Williamstown, the average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health threat from unsafe exposure to the Sun's UV rays.

Average temperature in December
Williamstown, MA

Average temperature in December - Williamstown, MA
  • Average high temperature in December: 32.7°F

The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in December: 22.1°F

The month with the highest average low temperature is July (57°F).
The coldest month (with the lowest average low temperature) is January (14.7°F).

[Resources]

Average pressure in December
Williamstown, MA

Average pressure in December - Williamstown, MA
  • Average pressure in December: 30.06"

The month with the highest atmospheric pressure is November (30.09").
The month with the lowest atmospheric pressure is June (29.92").

[Resources]

Average wind speed in December
Williamstown, MA

Average wind speed in December - Williamstown, MA
  • Average wind speed in December: 8.4mph

The windiest months (with the highest average wind speed) are January and February (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

[Resources]

Average humidity in December
Williamstown, MA

Average humidity in December - Williamstown, MA
  • Average humidity in December: 85%

The month with the highest relative humidity is February (86%).
The month with the lowest relative humidity is April (77%).

[Resources]

Average rainfall in December
Williamstown, MA

Average rainfall in December - Williamstown, MA
  • Average rainfall in December: 3.19"

The wettest month (with the highest rainfall) is October (3.62").
The driest month (with the least rainfall) is March (2.6").

[Resources]

Average rainfall days in December
Williamstown, MA

Average rainfall days in December - Williamstown, MA
  • Average rainfall days in December: 11.1 days

The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is February (7.8 days).

[Resources]

Average snowfall in December
Williamstown, MA

Average snowfall in December - Williamstown, MA
  • Average snowfall in December: 6.93"

The month with the highest snowfall is February (10").
Months with the least snowfall are June, July, August and September (0").

[Resources]

Average snowfall days in December
Williamstown, MA

Average snowfall days in December - Williamstown, MA
  • Average snowfall days in December: 11.2 days

The month with the highest number of snowfall days is February (15.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

[Resources]

Average daylight in December /
Average sunshine in December
Williamstown, MA

Average daylight in December / Average sunshine in December - Williamstown, MA
  • Average daylight in December: 9.1h

The month with the longest days is June (Average daylight: 15.3h).
The month with the shortest days is December (Average daylight: 9.1h).

  • Average sunshine in December: 3.8h

The month with the most sunshine is July (Average sunshine: 9.9h).
The month with the least sunshine is February (Average sunshine: 3.4h).

[Resources]

Average sunshine days in December
Williamstown, MA

Average sunshine days in December - Williamstown, MA
  • Average sunshine days in December: 11.7 days

The month with the most sunshine days is September (14.3 days).
The month with the least sunshine days is February (9 days).

[Resources]

Average UV index in December
Williamstown, MA

Average UV index in December - Williamstown, MA
  • Average UV index in December: 1

Months with the highest UV index are June, July and August (UV index 5).
Months with the lowest UV index are February and December (UV index 1).

[Resources]

Average cloud cover in December
Williamstown, MA

Average cloud cover in December - Williamstown, MA
  • Average cloud cover in December: 60

The month with the most cloud cover is February (Cloud cover 64).
Months with the least cloud cover are July and August (Cloud cover 38).

[Resources]

Average visibility in December
Williamstown, MA

Average visibility in December - Williamstown, MA
  • Average visibility in December: 5mi

Months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (5mi).
The month with the lowest visibility is February (4mi).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location